1. Field of the Invention
This invention relates to integrated multilayer materials for chemical analyses of liquid samples comprising a supporting plate having disposed thereon a plurality of different analytical units each unit fundamentally comprising a reagent layer and a spreading layer, and a common liquid delivering patch is provided so as to ensure delivery of the liquid sample to the spreading layer of each analytical unit by only one application of sample.
2. Description of the Prior Art
Inventions relating to multilayer analytical materials fundamentally comprising a reagent layer and a spreading layer are described in, for example, U.S. Pat. Nos. 3,526,480, 3,663,374, 3,983,005, 3,992,158, 4,042,335, 4,050,898 and 4,066,403 and Preparatory Papers for Publication at the 10th International Meeting of the Clinical Chemical Society (held in Mexico City, Feb. 26-Mar. 3, in 1978), pages 13, 14, 47, 76 and 118, etc. Such multilayer analytical materials incorporate an analytical reagent in a binder such as gelatin. In practice, all that is required for chemical analysis is to apply or adhere one drop of a test sample to the material. Thus, they are dry type chemical analysis materials requiring no reagent solutions, test tubes, etc.
The fundamental construction of these multilayer materials comprises a porous spreading layer and a reagent layer. In some cases, the reagent layer is made up of a plurality of sublayers sharing different functions, for example, where two reagents (such as in a two-step reaction) are required for analysis, a second reagent layer may be located under a first reagent layer; or the analytical reaction products may be registered in a layer separate from the reagents such as in a color-forming layer, a detecting layer, or a dye-receiving layer. Also, interlayers or so-called radiation-blocking layers, barrier layers, etc., may be provided between the plurality of reagent layers. Further, there are structures wherein a reagent is incorporated in the spreading layer and thus the spreading function and the assay function may be integrated. In any event, the two functions of sample-spreading and reagent analysis are fundamental.
A liquid sample dropped or applied onto multi-layered chemical analysis material is uniformly spread through the porous spreading layer as it reaches the surface of the reagent layer. The ingredient contained in the sample solution (analyte) or a by-product thereof reacts with the reagent and produces coloration or discoloration enabling optical chemical analysis and in particular colorimetric analysis, whereby the presence and the content of the ingredient contained in the sample solution is detected.
The above-described multilayer analytical materials are quite convenient for chemically analyzing a single chemical ingredient contained in a liquid sample such as saliva, blood, urine, etc., rapidly and easily in a dry manner without using test tubes and reagent solutions. With these materials, however, an exclusive analytical material is necessary for every item analyzed, for example, a different material would be required for determining glucose, urine nitrogen, and amylase in blood. Thus for the analysis of six blood ingredients such as bilirubin, albumin, and cholesterol in addition to the above three ingredients, six different multilayered materials must be selected, 5 .mu.l to 15 .mu.l of whole blood or serum must be dropped or applied to each of the six materials and, after the completion of color reaction, colorimetry must be sequentially conducted.
Multilayer chemical analysis materials are quite excellent from the standpoint of the easiness of the determination. For example, in the chemical analysis of blood, they are quite convenient for analyzing one item per patient. However, generally clinical chemical examinations check 5 to 10 times per patient per blood drawing in which case the above procedure of selection, application, and examination can become quite burdensome and complicated.